/*
 * Copyright 2020 HPB Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.hpb.bc.jmx;

import javax.management.MBeanServer;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.autoconfigure.condition.SearchStrategy;
import org.springframework.boot.autoconfigure.jmx.ParentAwareNamingStrategy;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableMBeanExport;
import org.springframework.context.annotation.MBeanExportConfiguration.SpecificPlatform;
import org.springframework.context.annotation.Primary;
import org.springframework.core.env.Environment;
import org.springframework.jmx.export.MBeanExporter;
import org.springframework.jmx.export.annotation.AnnotationJmxAttributeSource;
import org.springframework.jmx.export.annotation.AnnotationMBeanExporter;
import org.springframework.jmx.export.naming.ObjectNamingStrategy;
import org.springframework.jmx.support.MBeanServerFactoryBean;
import org.springframework.jmx.support.RegistrationPolicy;
import org.springframework.util.StringUtils;

/**
 * {@link EnableAutoConfiguration Auto-configuration} to enable/disable Spring's
 * {@link EnableMBeanExport} mechanism based on configuration properties.
 * <p>
 * To disable auto export of annotation beans set
 * {@code spring.jmx.enabled: false}.
 */
@Configuration
@ConditionalOnClass({MBeanExporter.class})
@ConditionalOnProperty(prefix = "spring.jmx", name = "enabled", havingValue = "true", matchIfMissing = true)
public class JmxAutoConfiguration implements EnvironmentAware, BeanFactoryAware {

    private Environment environment;

    private BeanFactory beanFactory;

    @Override
    public void setEnvironment(Environment environment) {
        this.environment = environment;
    }

    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        this.beanFactory = beanFactory;
    }

    @Bean
    @Primary
    @ConditionalOnMissingBean(value = MBeanExporter.class, search = SearchStrategy.CURRENT)
    public AnnotationMBeanExporter mbeanExporter(ObjectNamingStrategy namingStrategy) {
        AnnotationMBeanExporter exporter = new AnnotationMBeanExporter();
        exporter.setRegistrationPolicy(RegistrationPolicy.FAIL_ON_EXISTING);
        exporter.setNamingStrategy(namingStrategy);
        String serverBean = this.environment.getProperty("spring.jmx.server", "mbeanServer");
        if (StringUtils.hasLength(serverBean)) {
            exporter.setServer(this.beanFactory.getBean(serverBean, MBeanServer.class));
        }
        return exporter;
    }

    @Bean
    @ConditionalOnMissingBean(value = ObjectNamingStrategy.class, search = SearchStrategy.CURRENT)
    public ParentAwareNamingStrategy objectNamingStrategy() {
        ParentAwareNamingStrategy namingStrategy = new ParentAwareNamingStrategy(new AnnotationJmxAttributeSource());
        String defaultDomain = this.environment.getProperty("spring.jmx.default-domain");
        if (StringUtils.hasLength(defaultDomain)) {
            namingStrategy.setDefaultDomain(defaultDomain);
        }
        return namingStrategy;
    }

    @Bean
    @ConditionalOnMissingBean
    public MBeanServer mbeanServer() {
        SpecificPlatform platform = SpecificPlatform.get();
        if (platform != null) {
            return platform.getMBeanServer();
        }
        MBeanServerFactoryBean factory = new MBeanServerFactoryBean();
        factory.setLocateExistingServerIfPossible(true);
        factory.afterPropertiesSet();
        return factory.getObject();
    }

}